Diagnostic for a bad accumulator. Pressure test will verify loss of pressure on standing, with the result that it won't start until you get fuel pressure from the pump running.
The 3x on but don't crank will buzz the fuel pump three times for about a second each, and should restore most of the system pressure, so you have enough to spray the cold start valve when you crank.
Accumulater is under the floor of the car, next to the fuel filter, I think.
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!